remove unused WTF::dataLogFString function

third_party/WebKit/Source/wtf/DataLog.cpp

 /*
  * Copyright (C) 2012 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 81 matching lines @@
 }
 
 void dataLogF(const char* format, ...)
 {
     va_list argList;
     va_start(argList, format);
     dataLogFV(format, argList);
     va_end(argList);
 }
 
-void dataLogFString(const char* str)
-{
-    dataFile().printf("%s", str);
-}
-
 } // namespace WTF